> Inconsistent spacing after your bullet 'o', first two points have a> space the last two a tab or so.> > > Given that resched_cpu() is now used only by RCU, this commit fixes the> > assumption by making resched_cpu() unconditional.> > Other than that, yes looks _much_ better, thanks!> > Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>> > Also, you might want to tag it for stable.

The current implementation of synchronize_sched_expedited() incorrectly assumes that resched_cpu() is unconditional, which it is not. This means that synchronize_sched_expedited() can hang when resched_cpu()'s trylock fails as follows (analysis by Neeraj Upadhyay):